The present invention relates to a radio selection call receiver, and in particular, to a radio selection call receiver operative on the reception of a selection call signal including the ID code of the receiver for displaying a message subsequent to the ID code.
A radio selection call receiver (to be referred to as "receiver" hereinafter) is usually carried in a user's pocket or bag. Upon hearing the calling sound, the user presses a display switch and identifies messages personally. However, if the receiver is stolen or mislaid, a third person could see messages in the same way.
Japanese Laid-Open Patent Application No. 4-114522 entitled "Selection Call Receiver and Method for Displaying and Controlling Messages", for example, shows a receiver which maintains received message in secret. This invention is intended to provide a selection call receiver for ensuring security for messages received by the receiver while a user is absent, so that the messages will not be seen by the third person.
That radio selection call receiver comprises a control circuit for executing all the sequence control of the receiver, a radio circuit for receiving radio waves from the base station through an antenna, a demodulation circuit for demodulating signals received by the radio circuit, an ID-ROM for storing the individual number code (the ID code) of the receiver, a speaker driven by a speaker driving circuit to output a call sound, a message memory for storing received message codes, and a message display section for displaying a message when a display switch is pressed.
The control circuit comprises, for example, a microcomputer as a main control section and a message display control means, a secret mode control means, and a determination means as message display control functions.
When a call to the receiver occurs, the message display control means decodes the message code included in the selection call signal and causes a display control circuit to display a corresponding message on a display section. The determination means determines whether or not a received selection call signal includes a secret setting code or a secret cancellation code. When the determination means detects a secret setting code, the secret mode control means sets a secret mode to stop the message display control means from displaying the message. When a secret cancellation code is detected, the secret mode control means cancels the secret mode to permit the message display control means to control the display of message.
However, when the determination means detects a secret setting code and the secret mode control means stop displaying a message, the user has to transmit secret cancellation codes for each message, in order to identify received messages.